having the qualities of a good map; A north arrow to indicate orientation, a key to symbols, a scale indicator, color or shading to enhance features, tile, labels, landmarks and recognizable features.

Maps from the automobile club are highly mapular. Treasure maps are not, since they often leave out vital information to frustrate thieves.
(Does the map on its own tell you what you need to know: where you are, where you are going, how to get there?)